Germany - Cleaning and hygiene services

Description

Framework contract for services for flushing and cleaning the association's own drinking water pipeline network (without house connections).
In preparation for the changeover to "soft" water, extensive investigations were carried out by an accredited drinking water laboratory to assess the effects of the district water on the distribution network. For this purpose, various sections of pipeline from the distribution network were removed from the ground and subjected to tests on a test stand over several months. The presumed shifting of the surface layer in the distribution network, which can be associated with increased values for turbidity, colouration and iron loss, is seen as problematic. The Bad Langensalza waterworks association was therefore requested by the responsible health authorities to carry out preparatory work that would have a positive effect on the formation of the surface layer in the pipe network so that the drinking water quality would be disturbed as little as possible.To this end, the public health authorities have defined the following priorities for pipe network flushing in the supply area:1.1 All pipe networks in the member municipalities of the Association that are gradually being connected to the long-distance water supply must be flushed.1.2. all loose and detachable components in the distribution network of the communes shall be flushed from the pipe network.1.3. discharge of solid components from the pipes in order to reduce accumulation processes in the network for the formation of iron 3 - ions.1.4. flushing at a flow velocity of 2 m/s - 3 m/s, i.e. higher than the flow velocity in the existing network.1.5. flushing with water without air ingress to avoid additional oxygen ingress, by technically assisted increase of the flow velocity.1.6. avoiding total failure of the water supply, thus limiting the adverse effects on the final consumers.1.7. discharge of corrosion phenomena and rust water until the turbidity has disappeared.a total of approx. 150 km of TW pipes are expected to be flushed within the initial term of the contract; of these, 46 km are supra-local pipes and 104 km are inner-local pipes, excluding house connections.the proportion of heavily contaminated metallic pipes made of steel and cast iron is approx. 40 %, corresponding to 60 km. The remaining 60 % are easier to clean because they are non-metallic; these pipes are not or only slightly encrusted.

Opportunity closing date

26 October 2020

Value of contract

to be confirmed